java微信开发之上传下载多媒体文件

回复图片、音频、视频消息都是需要media_id的，这个是需要将多媒体文件上传到微信服务器才有的。

将多媒体文件上传到微信服务器，以及从微信服务器下载文件，可以参考：=上传下载多媒体文件

上传下载多媒体文件的方法还是写到weixinutil.java中。

代码如下：

import java.io.bufferedoutputstream;
import java.io.bufferedreader;
import java.io.datainputstream;
import java.io.dataoutputstream;
import java.io.file;
import java.io.fileinputstream;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.inputstream;
import java.io.inputstreamreader;
import java.io.outputstream;
import java.net.httpurlconnection;
import java.net.malformedurlexception;
import java.net.url;
import java.security.keymanagementexception;
import java.security.nosuchalgorithmexception;
import java.security.nosuchproviderexception;
import java.security.securerandom;
import java.util.calendar;
import java.util.date;
import java.util.hashmap;
import java.util.map;

import javax.net.ssl.httpsurlconnection;
import javax.net.ssl.sslcontext;
import javax.net.ssl.sslsocketfactory;
import javax.net.ssl.trustmanager;

import net.sf.json.jsonobject;

import org.apache.commons.lang.stringutils;
import org.apache.log4j.logger;

import com.company.project.model.menu.accesstoken;
import com.company.project.model.menu.menu;

public class weixinutil {
 private static logger log = logger.getlogger(weixinutil.class);
 public final static string appid = "wxb927d4280e6db674";
 public final static string app_secret = "21441e9f3226eee81e14380a768b6d1e";
 // 获取access_token的接口地址（get） 限200（次/天）
 public final static string access_token_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=appid&secret=appsecret";
 // 创建菜单
 public final static string create_menu_url = "https://api.weixin.qq.com/cgi-bin/menu/create?access_token=access_token";
 // 存放：1.token，2：获取token的时间,3.过期时间
 public final static map<string,object> accesstokenmap = new hashmap<string,object>();
 /**
 * 发起https请求并获取结果
 * 
 * @param requesturl 请求地址
 * @param requestmethod 请求方式（get、post）
 * @param outputstr 提交的数据
 * @return jsonobject(通过jsonobject.get(key)的方式获取json对象的属性值)
 */
 public static jsonobject handlerequest(string requesturl,string requestmethod,string outputstr) {
 jsonobject jsonobject = null;
 
 try {
 url url = new url(requesturl);
 httpsurlconnection conn = (httpsurlconnection) url.openconnection();
 sslcontext ctx = sslcontext.getinstance("ssl", "sunjsse");
 trustmanager[] tm = {new myx509trustmanager()};
 ctx.init(null, tm, new securerandom());
 sslsocketfactory sf = ctx.getsocketfactory();
 conn.setsslsocketfactory(sf);
 conn.setdoinput(true);
 conn.setdooutput(true);
 conn.setrequestmethod(requestmethod);
 conn.setusecaches(false);
 
 if ("get".equalsignorecase(requestmethod)) {
 conn.connect();
 }
 
 if (stringutils.isnotempty(outputstr)) {
 outputstream out = conn.getoutputstream();
 out.write(outputstr.getbytes("utf-8"));
 out.close();
 }
 
 inputstream in = conn.getinputstream();
 bufferedreader br = new bufferedreader(new inputstreamreader(in,"utf-8"));
 stringbuffer buffer = new stringbuffer();
 string line = null;
 
 while ((line = br.readline()) != null) {
 buffer.append(line);
 }
 
 in.close();
 conn.disconnect();
 
 jsonobject = jsonobject.fromobject(buffer.tostring());
 } catch (malformedurlexception e) {
 e.printstacktrace();
 log.error("url错误！");
 } catch (ioexception e) {
 e.printstacktrace();
 } catch (nosuchalgorithmexception e) {
 e.printstacktrace();
 } catch (nosuchproviderexception e) {
 e.printstacktrace();
 } catch (keymanagementexception e) {
 e.printstacktrace();
 }
 return jsonobject;
 }
 
 /**
 * 获取access_token
 *
 * @author qincd
 * @date nov 6, 2014 9:56:43 am
 */
 public static accesstoken getaccesstoken(string appid,string appsecret) {
 accesstoken at = new accesstoken();
 // 每次获取access_token时，先从accesstokenmap获取，如果过期了就重新从微信获取
 // 没有过期直接返回
 // 从微信获取的token的有效期为2个小时
 if (!accesstokenmap.isempty()) {
 date gettokentime = (date) accesstokenmap.get("gettokentime");
 calendar c = calendar.getinstance();
 c.settime(gettokentime);
 c.add(calendar.hour_of_day, 2);
 
 gettokentime = c.gettime();
 if (gettokentime.after(new date())) {
 log.info("缓存中发现token未过期，直接从缓存中获取access_token");
 // token未过期，直接从缓存获取返回
 string token = (string) accesstokenmap.get("token");
 integer expire = (integer) accesstokenmap.get("expire");
 at.settoken(token);
 at.setexpiresin(expire);
 return at;
 }
 }
 string requesturl = access_token_url.replace("appid", appid).replace("appsecret", appsecret);
 
 jsonobject object = handlerequest(requesturl, "get", null);
 string access_token = object.getstring("access_token");
 int expires_in = object.getint("expires_in");
 
 log.info("\naccess_token:" + access_token);
 log.info("\nexpires_in:" + expires_in);
 
 at.settoken(access_token);
 at.setexpiresin(expires_in);
 
 // 每次获取access_token后，存入accesstokenmap
 // 下次获取时，如果没有过期直接从accesstokenmap取。
 accesstokenmap.put("gettokentime", new date());
 accesstokenmap.put("token", access_token);
 accesstokenmap.put("expire", expires_in);
 
 return at;
 }
 
 /**
 * 创建菜单
 *
 * @author qincd
 * @date nov 6, 2014 9:56:36 am
 */
 public static boolean createmenu(menu menu,string accesstoken) {
 string requesturl = create_menu_url.replace("access_token", accesstoken);
 string menujsonstring = jsonobject.fromobject(menu).tostring();
 jsonobject jsonobject = handlerequest(requesturl, "post", menujsonstring);
 string errorcode = jsonobject.getstring("errcode");
 if (!"0".equals(errorcode)) {
 log.error(string.format("菜单创建失败！errorcode:%d,errormsg:%s",jsonobject.getint("errcode"),jsonobject.getstring("errmsg")));
 return false;
 }
 
 log.info("菜单创建成功！");
 
 return true;
 }
 
 // 上传多媒体文件到微信服务器
 public static final string upload_media_url = "http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token=access_token&type=type";
 /**
 * 上传多媒体文件到微信服务器<br>
 * @see http://www.oschina.net/code/snippet_1029535_23824
 * @see http://mp.weixin.qq.com/wiki/index.php?title=上传下载多媒体文件
 *
 * @author qincd
 * @date nov 6, 2014 4:11:22 pm
 */
 public static jsonobject uploadmediatowx(string filepath,string type,string accesstoken) throws ioexception{
 file file = new file(filepath);
 if (!file.exists()) {
 log.error("文件不存在！");
 return null;
 }
 
 string url = upload_media_url.replace("access_token", accesstoken).replace("type", type);
 url urlobj = new url(url);
 httpurlconnection conn = (httpurlconnection) urlobj.openconnection();
 conn.setdoinput(true);
 conn.setdooutput(true);
 conn.setusecaches(false);
 
 conn.setrequestproperty("connection", "keep-alive");
  conn.setrequestproperty("charset", "utf-8");
 
  // 设置边界
  string boundary = "----------" + system.currenttimemillis();
  conn.setrequestproperty("content-type", "multipart/form-data; boundary="
    + boundary);
 
  // 请求正文信息
 
  // 第一部分：
  stringbuilder sb = new stringbuilder();
  sb.append("--"); // ////////必须多两道线
  sb.append(boundary);
  sb.append("\r\n");
  sb.append("content-disposition: form-data;name=\"file\";filename=\""
    + file.getname() + "\"\r\n");
  sb.append("content-type:application/octet-stream\r\n\r\n");
 
  byte[] head = sb.tostring().getbytes("utf-8");
 
  // 获得输出流
  outputstream out = new dataoutputstream(conn.getoutputstream());
  out.write(head);
 
  // 文件正文部分
  datainputstream in = new datainputstream(new fileinputstream(file));
  int bytes = 0;
  byte[] bufferout = new byte[1024];
  while ((bytes = in.read(bufferout)) != -1) {
   out.write(bufferout, 0, bytes);
  }
  in.close();
 
  // 结尾部分
  byte[] foot = ("\r\n--" + boundary + "--\r\n").getbytes("utf-8");// 定义最后数据分隔线
 
  out.write(foot);
 
  out.flush();
  out.close();
 
  /**
   * 读取服务器响应，必须读取,否则提交不成功
   */
   try {
   // 定义bufferedreader输入流来读取url的响应
   stringbuffer buffer = new stringbuffer();
   bufferedreader reader = new bufferedreader(new inputstreamreader(
   conn.getinputstream()));
   string line = null;
   while ((line = reader.readline()) != null) {
   buffer.append(line);
   }
   
   reader.close();
   conn.disconnect();
   
   return jsonobject.fromobject(buffer.tostring());
   } catch (exception e) {
   log.error("发送post请求出现异常！" + e);
   e.printstacktrace();
   }
 return null;
 }
 
 public static final string download_media_url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=access_token&media_id=media_id";
 /**
 * 从微信服务器下载多媒体文件
 *
 * @author qincd
 * @date nov 6, 2014 4:32:12 pm
 */
 public static string downloadmediafromwx(string accesstoken,string mediaid,string filesavepath) throws ioexception {
 if (stringutils.isempty(accesstoken) || stringutils.isempty(mediaid)) return null;
 
 string requesturl = download_media_url.replace("access_token", accesstoken).replace("media_id", mediaid);
 url url = new url(requesturl);
 httpurlconnection conn = (httpurlconnection) url.openconnection();
 conn.setrequestmethod("get");
 conn.setdoinput(true);
 conn.setdooutput(true);
 inputstream in = conn.getinputstream();
 
 file dir = new file(filesavepath);
 if (!dir.exists()) {
 dir.mkdirs();
 }
 if (!filesavepath.endswith("/")) {
 filesavepath += "/";
 }
 
 string contentdisposition = conn.getheaderfield("content-disposition");
 string weixinserverfilename = contentdisposition.substring(contentdisposition.indexof("filename")+10, contentdisposition.length() -1);
 filesavepath += weixinserverfilename; 
 bufferedoutputstream bos = new bufferedoutputstream(new fileoutputstream(filesavepath));
 byte[] data = new byte[1024];
 int len = -1;
 
 while ((len = in.read(data)) != -1) {
 bos.write(data,0,len);
 }
 
 bos.close();
 in.close();
 conn.disconnect();
 
 return filesavepath;
 }
}

测试代码：

public class weixinutiltest {

 /**
 *
 * @author qincd
 * @date nov 6, 2014 9:57:54 am
 */
 public static void main(string[] args) {
 // 1).获取access_token
 accesstoken accesstoken = weixinutil.getaccesstoken(weixinutil.appid, weixinutil.app_secret);
 string filepath = "c:\\users\\qince\\pictures\\壁纸20141029091612.jpg";
 jsonobject uploadjsonobj = testuploadmedia(filepath,"image",accesstoken.gettoken());
 if (uploadjsonobj == null) {
 system.out.println("上传图片失败");
 return;
 }
 
 int errcode = 0;
 if (uploadjsonobj.containskey("errcode")) {
 errcode = uploadjsonobj.getint("errcode");
 }
 if (errcode == 0) {
 system.out.println("图片上传成功");
 
 string mediaid = uploadjsonobj.getstring("media_id");
 long createat = uploadjsonobj.getlong("created_at");
 system.out.println("--details:");
 system.out.println("media_id:" + mediaid);
 system.out.println("created_at:" + createat);
 }
 else {
 system.out.println("图片上传失败！");
 
 string errmsg = uploadjsonobj.getstring("errmsg");
 system.out.println("--details:");
 system.out.println("errcode:" + errcode);
 system.out.println("errmsg:" + errmsg);
 }
 
 string mediaid = "6w-uvsrq2hkdsdvqjjxshwtfdplfbgi1qnbnfy8wezyb9jac2xxxcauwt8p4syph";
 string filepath = testdownloadmedia(accesstoken.gettoken(), mediaid, "d:/test");
 system.out.println(filepath);
 }


 /**
 * 上传多媒体文件到微信
 *
 * @author qincd
 * @date nov 6, 2014 4:15:14 pm
 */
 public static jsonobject testuploadmedia(string filepath,string type,string accesstoken) {
 try {
 return weixinutil.uploadmediatowx(filepath, type, accesstoken);
 } catch (ioexception e) {
 e.printstacktrace();
 }
 
 return null;
 }
 
 /**
 * 从微信下载多媒体文件
 *
 * @author qincd
 * @date nov 6, 2014 4:56:25 pm
 */
 public static string testdownloadmedia(string accesstoken,string mediaid,string filesavedir) {
 try {
 return weixinutil.downloadmediafromwx(accesstoken, mediaid, filesavedir);
 } catch (ioexception e) {
 e.printstacktrace();
 }
 
 return null;
 }
}

更多精彩内容请点击《android微信开发教程汇总》，《java微信开发教程汇总》欢迎大家学习阅读。

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